A frictionless pendulum has a length of 1.2 m and a mass of 0.8 kg. If the pendulum is raised to an angle of 50 degrees before it is released, then what is the pendulum’s gravitational potential energy at the point of release?(1 point)
Responses
3.4 J
3.4 J
2.2 J
2.2 J
0.34 J
0.34 J
6.0 J
The formula for gravitational potential energy is PE = mgh, where m is the mass, g is the acceleration due to gravity (9.8 m/s^2), and h is the height. In this case, we need to find the height.
The height can be found using trigonometry, since the pendulum is raised to an angle of 50 degrees. The length of the pendulum (L) can be used as the hypotenuse of a right triangle, with the height (h) being the adjacent side.
Using cosine, we can find the height:
cos(50) = h / 1.2
h = 1.2 * cos(50) ≈ 0.776
Now we can calculate the gravitational potential energy:
PE = mgh
PE = 0.8 * 9.8 * 0.776
PE ≈ 6.0 J
Therefore, the correct answer is 6.0 J.